radcrypt: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/radcrypt - from package: freeradius-utils

You may install the required package with command yum install {package}
Error in other languages:
radcrypt: bevel nie gevind nie
radcrypt: comandă negăsită
radcrypt: comando não encontrado
radcrypt: commande introuvable
radcrypt: command not found
radcrypt: käsku ei ole
radcrypt: không tìm thấy lệnh
radcrypt: komanda nerasta
radcrypt: Kommando nicht gefunden.
radcrypt: kommandot finns inte
radcrypt: komut yok
radcrypt: nie znaleziono polecenia
radcrypt: níor aimsíodh an t-ordú
radcrypt: no se encontró la orden
radcrypt: no s'ha trobat l'ordre
radcrypt: opdracht niet gevonden
radcrypt: parancs nem található
radcrypt: perintah tidak ditemukan
radcrypt: príkaz nenájdený
radcrypt: příkaz nenalezen
radcrypt: команда не найдена
radcrypt: командата не е открита
radcrypt: 命令找不到
radcrypt: コマンドが見つかりません